Poor performance when using urtwn on beaglebone black

[Otacílio]

Dears

I'm getting poor performance when using wifi by urtwn on beaglebone 
black. I'm using netperf to do benchmarks and I'm getting less than 
1Mbps normally and between 3Mbps and 7.5Mbps when creating the interface 
with -ht option. I think that previous versions has better performance.

FreeBSD beaglebone 11.0-ALPHA4 FreeBSD 11.0-ALPHA4 #0 r302064: Wed Jun 
22 00:25:52 BRT 2016 
ota at squitch:/root/workdir/crochet/work/obj/arm.armv6/usr/src/sys/BEAGLEBONE 
arm

[]'s

-Otacílio